Drill-head.



CLARENCE E. REED, 0F HOUSTON, TEXAS.

DRILL-HEAD.

Specification of Letters Patent. Patented Sept, 24, 1918,

Application led June 5, 1918. Serial No. 238,328.

To all whom 'it may concern:

Beit known that I, CLARENCE E.v REED, a citizen of the United States, and resident of Houston, Texas, have invented certain new and useful Improvements in Drill- Heads, of whichthe following is a specification.

My invention is an improvement in the general type of drill for drilling wells shown for instance in Letters Patent of the United States, No. 1,120,198, December 8th, 1914, granted to Humason, and my im provement concerns particularly the mountlng ofthe journal pin on which the side cutters turn.

The invention is shown in the accompanying drawing which represents a vertical sectional view ofthe drill head.

This type of drill has cutters 1 arranged in recesses 2 extending upwardly and inwardly at an inclination or toward the ver tical axis of the drill head, and thedrill head has a central space 3 in which the main cutter 4 is located.

The cutters 1-turn about journal pins 5 which are fixed in the walls 6 and 7, defining the inner and outer sides of the slots 2.

These pins have conical heads 5 and screw-threaded ends 5" and in the improved arrangement I place the pins in positon =b inserting them from the recess 3 outwar ly instead of inserting them from the outer side of the head, and of course the pins are placed before the main cutter member is positioned.`

The wall 6 at the inner side of the slot'2 is provided with a conical seat for receiving the conical head Sfof the pin and the outer wall 7 of the recess is screw-threaded to receive the screw-threaded end of the pin.

In some prior constructions in which the pin was inserted from the outside of the drill'head it has been customary to employ some safety device at the outer or headed end of the pin, such as a screw or pin to prevent the bearing pin from worklng out of place, but with my `arrangement the in cannot work out of place or dro out ecause of the presence of. the main cutter, which extends across the inner headed end of the pin with its periphery working close thereto. Further the space at the outer bearngwall 7 Vwhich heretofore has been occupied by the safety device is with -my arrangement available lfor threading to receive the screw-threaded end of the pin, and this, together with the extra thickness of the outer wall 7 in relation to the inner wall 6 gives a longer threaded seat to receive the threaded end of the pin than` is possible under the old arrangement and thus a stronger tie is provided between these walls 6 and 7, and one which will be maintained because. as above stated the pin cannot work out of place, this being prevented by the main cutter Working close to the inner headed end of the pin. Further the beveled head of the pin having a wider bearing contact with the thin inner wall 6 than is possible Wit-h a threaded connection acts to better sustain this Wall and make a more reliable support to take the strains than under previous constructions in which the threaded end ofthe pin finds a comparatively short bearing in the said wall only a few threads being available.

With my improvement even ythou h a journal pin might break the cutter wil not be lost in` the well for the reason that the pieces of the pin would still be held in place and thus retain the cutter, though of course the cutter might not function as intended and repairs would have to be made.

A double shearing or cutting of the pin on af straight line at :theinner walls of the slot would be' necesseryto permit the cutter to drop out of the recess, and this isa possibility which is most remote as the leverage would cause the pin to break first near the wall of the slot nearest the axis of the drill head, and then the cutter would have enough play or lateral movement to prevent shearing the pin near the outer wall ofthe slot prior to the bit being Withdrawn from the well.

What I claim is:

1. A drill having a head with a central recess and laterally disposed slots, rotary f cutters in the slots, a main cutter in the 'central recess and 'ournal pins for the rotary cutters extending across the slots and having theirheads bearing against the inner walls of the slots adjacent the central outter, and their outer ends bearing in the outer walls of the slots, said pins being inserted into place through the central recess 'of the drill head, substantially as described.

2. A drill having a head with a central recess and laterally disposed slots, rotary cutters in the slots, a main cutter in the loe central recess and journal pins for the roofthe drill head, said pin heads being of tary cutters extending across the slots and rusto-conical form and fitting correspondhaving their heads bearing in the inner ing seats in the said inner walls and having 10 walls of the slots adjacent the central their outer ends threaded into said outer 5 cutter, and their outer ends bearing in the walls, substantially as described.

outer walls of the slots, said pins being in- In testimony whereof I aix my signature. -serted into place through the central recess CLARENCE E. REED. 

